Drilling shock absorber



United States Patent O 3,122,902 DRILLING SHOCK ABSORBER Robert A. Blair and Hubert H. Wagnon, Hobbs, N. Mex., assignors to Drilprodco, Inc., a corporation of New Mexico Filed Aug. 28, 1961, Ser. No. 134,519 Claims. (Cl. 64-23) The device of the present invention relates to a new and improved shock absorber for drilling. and more particularly to a device adapted to be positioned on a drill string just above the drill bit or other tool to thereby absorb any shock that might be transmitted from the drilling bit or other tool to the drill string.

In the usual oil well drilling operations, any shock or jarring action occurring at the drill bit during drilling is transferred to the drill pipe and any apparatus connected therewith or mounted therein. Serious damage and interference with satisfactory drilling operations often results from such transmission of shock or jarring action.

lt is therefore an object of the present invention to provide a new and improved shock absorbing apparatus which may be positioned in a drill string or the like just above the drill bit or other tool which inhibits or reduces the transmission of shock from the drill bit or such other tool to the drill string or the like.

Another'im-portant object of thepresent invention is to providean apparatus which not only absorbs or inhibits shock from the drill bit or other tool, but also transmits torque to the drill bit or other tool, all without interfering with the drilling operations.

Still another object of the present invention is to provide a new and improved apparatus for absorbing shocks indrill strings and the like which may be quickly and easily positioned on a drill string just above the drill bit or other tool for absorbing any shock transmitted thereby.

Still another object of the present invention is to provide a new and improved shock absorber for drill strings and the like wherein a mechanical means is used to absorb any shock transmitted from the drill bit or other tool to the drill string.

A further object ofthe present invention is to provide a new and improved shock absorber for drill strings and the like wherein a spring adapted to withstand tests in excess of 100,000 pounds of pressure is used to absorb the shock from the drill bit or other tool to the drill string and to also transmit torque from the drill string to the drill bit or other tool.

Yet a further object of the present invention is to provide a new and improved shock absorber for drill strings and the like having a safety connection or means thereon for enabling the drill bit or tool positioned below the shock absorber to be retrieved in the event of failure or breaking of the shock absorber spring or the like.

Yet a further object o f the present invention is to provide a new and improved shock absorbing apparatus for drill strings and the like which eliminates the need for splines thereon which tend to break olf and necessitate costly fishing jobs. j

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and

. wherein:

FIG. 1 is a view in elevation, illustrating the device of the present invention in position on a drill string just above a drill bit; and

ice

FIG. 2 is a sectional view taken on line 2 2, illustrating the details of the device of the present invention.

Referring now to the drawings, and more especially to FIG. l, the device of the present invention is indicated at A, and is illustrated in position on a drill string 5 in a well W. A drilling bit 6 is attached or connected to the lower end of the drill string 5 in the usual manner and is on the drilling surface 7 in the well W. The shock absorber A is connected to the drill string 5 by any suitable means such as the female or box end 8 engaging the pin 9 and is preferably positioned in the drill string 5 immediately above the drilling bit 6 or other tool or device which might be employed. The drill bit 6 also connected to the lower end of the apparatus A by any suitable means such as the male end or pin 9 which is engaged in the opening 6a in the drill bit 6. The apparatus A has a safety covering or housing 10 thereon which is preferably comprised of an upper section 10a and a lower section 10b which are connected or joined together by any suitable means such as threads or the like which provide for assembly and access to the body 11 (see FIG. 2). The'details of the apparatus A will be discussed hereinafter.

The apparatus A, as viewed in FIG. 2, includes the body l1, which has an upper body or tubular member l2 and a similar lower body or tubular member 13 which are joined together by a substantially heavy duty spring 14 which is positioned longitudinally between the upper body 12 and the lower body 13 and is secured to such upper and lower bodies by welding or other suitable means.

To facilitatevthe connection of the spring 14I to the upper and lower bodies 12 and 13, respectively, internally threaded rings 15 and 16 are welded or otherwise secured to the ends 14a and 14h, respectively, of the spiing 14, thereby enabling the spring 14 to be quickly and easily secured on the upper and lower body portions er members 12 and 13. The upper body 12 and the lower body 13 have threaded end portions 12x and 13x, respectively, for receiving the internal threads 15a and 16a, respectively. lnstead of using the rings 15 and 16, the spring 14 can be attached or secured directly to the bodies 12 and 13, if desired, without departing from the scope of the invention.

The spring 14 is illustrated in its normal or rest position and is constructed of such strength and resiliency that when the device A is used in drilling operations' the spring 14 will be compressed. so that the various shock loads or jars on thc drill bit are absorbed by the spring 14.

The spring 14 is of the heavy duty type, and is preferably able to withstand a compressive force of from 100,000 to 150,000 pounds before completely collapsing. It should be understood, however, that the spring or resilient means 14 of the present invention A is not limited to springs of such strengths. Also, other suitable resilient means may be used in place of the spring 14 so long as it is capable of transmitting torque and absorbing shock loads.

The upper body 12 has a longitudinal opening 12a therein which permits the passage of drilling liuid from the top of the well to the drill bit in drilling operations. The lower body 13 has a longitudinal opening 13a therein for the same purpose and which is in substantial alignment with the longitudinal opening 12a in the body 12.

ln one form of the invention, a central tubular member 18 is positioned in the longitudinal openings 12a and 13a and is also in substantial alignment with such openings 12a and 13a. One end 18a has threads l8b thereon which are adapted to be received by similar threads 12b in the lower end 12e of the body l2. The opening 12a is also preferably in direct alignment with the inner surface 18e of thc central tubular member or means )18. The threaded connection between tubular member 1 8 and the body 12 provides a seal therebetween at the upper end of the member 18 to prevent uid flow externally of the member 18 from the passage 12a. The upper end 18d of the member 18 preferably seats against a tapered stop surface A12d in the upper body 12. The lower end 18e of the tubular member 18 is slidably positioned in the opening 13a of the lower body 13 so that the inner surface 13a of the lower tubular member 13 moves adjacent or over the outer surface -18f of the central tubular member 18. Suitable seal means such as rubber O-rings 19 and 20 are positioned in annular grooves or recesses 21 and 22, respectively, in the lower body 13 for providing a seal between the central tubular member 18 and the lower tubular member 13. The lower body 13 is longitudinally movable relative to the central tubular member 18 while the seal with rings 19 and 20 is maintained. The body 13 is shown in its uncompressed position. When the spring 14 is placed under compression due to shock -loads from the bit 6, the body 13 is moved upwardly relatively to the central tubular member 18. The seal means -19 and 20 thus continue to seal the tubular member 18 from the lower body 13 at all times so that any fluid in the tubular member 18 or lower body 13 will not be communicated with the spring 14 or the area 24 around the spring 14.

In an alternative form of the invention, the tubular member 18 may be omitted, in which case, fluid is permitted into the area 24 so that the apparatus provides a combination mechanical-hydraulic shock absorber, as will be explained hereinafter.

The body 13 has an extended portion 13b which is adapted to be connected to a drilling tool such as a drilling bit 6. Any shock received by the drilling bit 6, causes the body 13 to be moved upwardly against the spring 14 to thereby compress such spring 14 and thereby absorb ythe shock, thus preventing such shock from being transmitted throughout the entire drill string.

lThe upper portion or body 12 is adapted to be connected to a drilling string or the like and has an extended portion or stem 12y to which a tubing member or drill string may be quickly and easily attached. The stem 12)' is illustrated as having a box or female end 8 thereon -which is adapted to receive the male lmember or pin 9 of the drill string 5. It can be appreciated that the connection end 8 as -well as the connection end 9' may be varied as desired without departing from the scope of the present invention.

The safety means or outer covering is preferably cylindrical and comprises two parts 10a and 10b for facilitation in assembly and also in the repair and rcplacement of parts of the apparatus A. The sleeve parts 10a and 10b are similarly constructed except that one part 10a is somewhat longer than the other 10b. Such construction is a matter of choice and enables the spring '14 too be covered by a single outer covering. The sleeve or coverings 10a and 10b have enlarged or stepped-in end portions 10a' and 10b which are slidably engaged on the bodies 12 and 13, respectively. Seal means such as O- rings 26 and 27 seated in the openings or grooves 28 and 29, respectively, assure that the sleeve 10 is secure-ly sealed on the body lvl. The spring 14 is thus protected externally from any foreign matter or undesirable fiuids.

The body portions 12 and 13 have shoulders 12j and 13f respectively, thereon which serve as stops to limit the amount of travel or movement of the sleeve 10 on the body 1l. In order to retain the sleeve in a centered position on the body 1l. suitable centering means such as the springs 30 and 31 Aare mounted or positioned o-n the bodies 12 and 13, respectively. 31 are preferably identical and are of sufficient strength and resiliency to keep the sleeve V10 substantially centered on the body 1l. Springs testing about 200 pounds have been found to be very satisfactory. One end of the'spring 30 is adjacent the shoulder 12/ of the body 12 and the The springs 30 and other end of the spring is adjacent the shoulder 10a" of the sleeve portion 10a. The spring 31 is similarly mounted with one end adjacent the shoulder 13f of the body 13 and the other end adjacent the shoulder 10b" of the sleeve part 10b.

The springs 30 and 31 are illustrated in their static or uncompressed position and it can easily be seen that the springs 30 and/or 31 as the case may be will tend to center the sleeve 10 on the body 1l. Should either the sleeve 10 or the body 1l be moved in relation to one another, either the spring 30 or the spring 31 will act to return the sleeve 10 and body 11 to their normal or centered position with respect to each other.

The sleeve or safety covering 10 not only connects the upper body 12 and the lower body 13 to each other, but also perm-its the spring 14 to be compressed or to absorb shock. Although the apparatus A can be used without `the covering 10, such covering 10 assures that in the event of failure or breaking of the spring 14, no part of the apparatus A is lost in the Iwell hole nor are any tools or drill bits which might =be connected to the apparatus A. Such tools or drill bits are still firmly secured to the apparatus A and can easily be removed from the hole. Costly fishing operations are therefore eliminated. In addition to providing for a practical safety means, the sleeve 10 also protects the internal working parts of the apparatus from being contaminated by foreign matter.

When the tubular member 18 is omitted in the combination mechanical-hydraulic form of the invention, fluid enters the area 24. The fluid in the area 24 assists the spring 14 in further cushioning shock and gives the ap` paratus A a partial hydraulic ef'fect in addition to the mechanical action of the spring -14.

Although, it is believed that the use of the present invention is readily apparent from the foregoing description, a brief summary of the use of the apparatus A is set forth hereinafter.

In the drilling of an oil well or the like, the apparatus A is preferably connected to the lower end of the drill string 5 just above the drill bit 6. The weight of the drill string 5 is transmitted to the bit 6 through the body 12, spn'ng 14 and body 13. As the drill string is rotated, the spring 14 is tightened since it is a left hand spring. Such tightening of the spring tends to place it under some initial compression but because of the strength of the spring, it does not collapse. Therefore, there are spaces 14e as shown between the coils of the spring 14 even when torque is applied thereto.

Thus, under normal drilling operations, the spring 14 is not fully compressed so that there is always some resiliency in such spring 14 to absorb any shock or jar rwhich might be received from the drill bit 6 during drilling operations. The apparatus A thus provides an effective means of cushioning or absorbing any shock or jar which might otherwise be transmitted Ithroughout the entire drilling stning while at the same time transmitting the weight of the drill string and the torque therefrom to the drill bit.

The foregoing disclosure and description of the inveni tion is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

l. A shock absorbing device adapted to be positioned in a drill string or the like and rotated therewith, comprising a body having a longitudinal opening therethrough, said body having an .upper tubular member and a lower tubular member longitudinally spaced from each other, n fluid conductor pipe connected to one of said tubular members and slidably disposed in the other of said tubular members for conducting fluid through said body even though relative longitudinal movements of said tubular members occur, resilient torque means on said body connecting said upper tubular and said lower tubular member for enabling said members to be moved longitudinallywith respect to each other and for enabling said members to be rotated substantially in unison about a longitudinal axis, and a safetyy housing on said body connecting said upper tubular member and said lower tubular member for preventing separation of said members upon breaking of said resilient means.

2. A device for positioning in a drill string or the like for absorbing shock transmitted during drilling operations, comprising an upper body having a longitudinal passage therethrough, a lower body having a longitudinal passage therethrough, a heavy duty left hand wound spring secured to said upper body and to said lower body and in longitudinal alignment with said bodies and adapted to be wound tightly under compression upon a rotation of said upper body, said spring having voids between its convolutions when said upper body and said lower body are spaced apart the maximum longitudinal distance and being sufliciently resilient to reduce said voids to enable either of said bodies to be moved longitudinally with respect to cach other, said spring being suliciently strong to enable said bodies to be rotated substantially in unison with each other, means on said upper body for connecting said upper body to a drill string member, and means on said lower body for connecting said lower body to n drill string member.

3. A device for positioning in a drill string or the like for absorbing shock transmitted during drilling operations, comprising an upper body having a longitudinal passage therethrough, a lower body having a longitudinal passage therethrough, a heavy duty spring secured to said upper body and to said lower body and in longitudinal alignment with said bodies, said spring being sufficiently resilient to enable said bodies to be moved longitudinally with respect to cach other, said spring being sufliciently strong to enable said bodies to be rotated substantially in unison with each other, means on said upper body for connecting said upper body to a drill string member, means on said lower body for connecting said lower body to a drill string member, a tubular member positioned in said longitudinal passage in said upper body and said lower body, said tubular member being connected to said upper body and in fixed relationship therewith, said tubular member extending through said spring and slidably positioned in relationship with said lower body, said tubular member slidably extending below the upper end of said lower body for substantially preventing communication of fluid from said longitudinal passages to said spring, a safety covering slidably mounted on said upper and lower bodies, and means on said upper and lower bodies for limiting the longitudinal movement of said safety covering on said upper and lower bodies.

4. The structure recited in claim 3, including stop means on said upper and lower bodies for substantially maintaining said safety covering in a centered position on said upperand lower bodies.

5. A shock absorbing device adapted to bc positioned in a. drill string or the like and rotated therewith, comprising a body having a longitudinal opening therethrough,

said body having an upper tubular member and a lower tubular member, resilient torque means on said body connecting said upper tubular and said lower tubular member for enabling said members to be moved longitudinally with respect to each other and for enabling said members to be rotated substantially in unison about n longitudinal axis, f'a safety housing on said bodyconnecting said upper tubular member on said lower tubular member for preventing separation of said members upon breaking of said resilient means, and additional resilient means in tho upper and lower portions of said housing 'engaging the upper and lower tubular 'members respectively or substantially centering said housing with respect to said resilient torque means.-

6. A device for positioning in a drill string or the like for absorbing shock transmitted during drilling operations, comprising an upper body having a longitudinal passage therethrough,`a lower body having a longitudinal passage therethrough, a heavy duty spring secured to said upper body and to said lower body and in longitudinal alignment with said bodies, said spring being suflicicntly resilient to enable either of said bodies to be moved longitudinally with respect to each other, said spring being sufficiently strong to enable said bodies to be rotated substantially in unison with each other, means on said upper body for connecting said upper body to a drill string member, means on said lower body for connecting said lower body to a drill string member, a tubular member positioned in said longitudinal opening in said upper body, said'tubular member being connected to said upper body and in fixed relationship therewith, said tubular member extending through said spring and slidably positioned in said longitudinal opening in said lower body, and said tubular member substantially preventing the communication of fiuid from said longitudinal openings with said spring.

7. A device for positioning in a drill string or the like for absorbing shock transmitted during drilling operations, comprising an upper body having a longitudinal passage therethrough, a lower body having a longitudinal passage therethrough, a heavy duty spring secured to said upper body and to said lower body and in longitudinal alignment with said bodies, said spring being sufliciently resilient to enable either of said bodies to be moved longitudinally with respect to each other, said spring being sufliciently strong to enable said bodies to be rotated substantially in unison with each other, means on said upper body for connecting said upper body to a drill string member, means on said lower body for connecting said lower body to a drill string member, a safety covering slidably positioned on said upper and lower bodies for preventing the complete separation of said bodies in the event said spring is broken, and means on said upper and lower bodies for limiting the longitudinal movement of said safety covering on said upper and lower bodies.

8. The structure recited in claim 7, including means on said upper and lower bodies for substantially maintaining said safety covering in a centered position on said upper and lower bodies.

9. A shock absorbing device adapted to be positioned in a drill string or the like and rotated therewith, comprising n body having a longitudinal opening therethrough, said body having an upper portion and a lower portion, resilient means on said body connecting said upper portion of said body with said lower portion of said body, a substantially rigid tubular housing extcriorly of said body and said resilient means, means slidably connecting said tubular housing to said body to maintain the longitudinal axes of said body and said resilient means in substantial alignment at all times while said portions of said body are moved longitudinally in relationship to each other, and a tubular member in said longitudinal opening in said body having one end connected to one of said portions of said body and adapted to be moved therewith and having another end slidably engaged with the other of said portions.

l0. The structure recited in claim 9, including means on said body for substantially maintaining said housing on said body in a centered position.

References Cited in the tile of this patent UNITED STATES PATENTS 1,459,223 Lanzius .lune 19, 1923 1,960,688 Archer May 29, 1934 2,325,132 Haushalter July 27, 1942 2,536,216 Powell Jan. 2, 1951 2,666,307 Higert Jan. 19, 1954 2,701,456 Brownstein Feb. 8, 1955 

1. A SHOCK ABSORBING DEVICE ADAPTED TO BE POSITIONED IN A DRILL STRING OR THE LIKE AND ROTATED THEREWITH, COMPRISING A BODY HAVING A LONGITUDINAL OPENING THERETHROUGH, SAID BODY HAVING AN UPPER TUBULAR MEMBER AND A LOWER TUBULAR MEMBER LONGITUDINALLY SPACED FROM EACH OTHER, A FLUID CONDUCTOR PIPE CONNECTED TO ONE OF SAID TUBULAR MEMBERS AND SLIDABLY DISPOSED IN THE OTHER OF SAID TUBULAR MEMBERS FOR CONDUCTING FLUID THROUGH SAID BODY EVEN THOUGH RELATIVE LONGITUDINAL MOVEMENTS OF SAID TUBULAR MEMBERS OCCUR, RESILIENT TORQUE MEANS ON 